The experiments in this proposal will provide information on the alteration of interhemispheric connections and cortical function which result from strabismus, and they will increase our understanding of the mechanisms which underlie binocular vision. Anatomical methods will be used to determine the relation between the degree and direction of aquint and the abnormal connection of the corpus callosum. The time course and critical period of development of abnormal callosal connections in strabismic animals will be determined. The connections of the corpus callosum will be studied in animals with reduced cortical binocularity. The anatomical methods for these experiments will include retrograde transport of horseradish peroxidase and anterograde transport of proteins synthesized from tritiated amino acids. The horseradish peroxidase will be visualized by the tetramethyl-binzidine technique. Labeled proteins will be visualized by audioradiography. Electrophysiological methods will be used to study the representation of the visual field in primary cortex in a mutant with a naturally occuring strabismus, the Siamese cat. The role of the corpus callosum in maintaining cortical binocularity in normal animals will be determined by recording from single units and studying their response properties in animals which have undergone section of the corpus callosum. The response properties of single callosal axons will be studied in normal and strabismic animals. These experiments will increase our understanding of the role of experience in the development of the brain. They will also increase our understanding of the role of the corpus callosum in communicating information between the two halves of the brain.